Device for removing wet paint overspray

ABSTRACT

The invention relates to a device for removing wet paint overspray from an outgoing air flow ( 120 ) containing over-spray particles. The device separates wet paint over-spray from an over-spray particle contained in an exhaust air stream ( 120 ). The overspray particles in the exhaust air stream ( 120 ) are formed during the painting at an application area ( 108 ) of a painting installation ( 100 ). The device ( 126 ) comprises of at least one separation apparatus for separating the over-spray from the exhaust air stream ( 120 ). The separation apparatus includes a regeneratable surface filter ( 146 ) and the flow path of the exhaust air stream ( 120 ) from the application area ( 108 ) to a separating device ( 145 ) having at least one narrowed area ( 146 ). The central direction of flow of the exhaust air stream ( 120 ) remains essentially preserved in passing by the narrowed area ( 140 ).

PRIOR APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 11/886,764 filed on Jan. 23, 2009, which is a National Stageof, and claims priority to and all advantages of International PatentApplication No. PCT/EP2006/002469 filed Mar. 17, 2006, on the basis ofGerman Patent Application No. DE10/2005/013711.3 filed on Mar. 24, 2005.

TECHNICAL FIELD

The present invention relates to a device for removing wet paintoverspray from an exhaust air flow containing over-spray particles,whereby the over-spray particles in the exhaust air flow reach into anapplication area of a painting installation.

TECHNICAL BACKGROUND

Such devices are used in plants for painting work parts, in particularfor spray-painting vehicle bodies, in which an air flow is produced byan application area of the plant, which exhausts excess wet paint fromthe application area.

It is well-known to separate out the carried wet paint over-spray of awashing plant from the exhaust air flow by means of a washing liquid.

Known washing plants have the disadvantage, however, in particular withair circulation control, in that a high amount of moisture is suppliedto the exhaust air flow from which the wet paint over-spray isseparated, so that the exhaust air flow resulting after separation ofthe wet paint over-spray must be subjected to a energy-intensivedehumidification.

Furthermore, greater expense is required for the treatment of thewashing liquid loaded with the wet paint over-spray.

The basic object of the present invention is to provide a device of theaforementioned type which enables a separation of the wet paintover-spray from the exhaust air flow in a simple, reliable andenergy-saving way.

This problem is solved according to the invention with a device havingthe characteristics of the generic terms of claim 1, in that the devicecomprises at least one separation apparatus for separating theover-spray from at least one part of the exhaust air flow, which has atleast one regeneratable surface filter, and that the flow path of theexhaust air flow from the application area to the separating apparatuscomprises at least one narrowed area, whereby the central direction offlow of the exhaust air flow remains essentially preserved in passingthe narrowed area.

A regeneratable filter is understood to be one which has a filtersurface upon which the wet paint over-spray carried by the exhaust airflow is separated-off, and that, preferably during the operating processof the device, is cleanable from the separated-off paint over-spraythereon.

Such a regeneratable surface filter is a “dry” separation device inwhich no liquid is used for washing the over-spray particles out of theexhaust flow, but instead filter elements are used for separation of theover-spray particles from the air flow.

Thereby, cleaning of the regeneratable surface filter by means of a“dry” separation device can take place, that is, without using acleaning fluid or a “wet” cleaning device which utilizes a liquid.

A “dry” separation device can also be provided with “wet” cleaningapparatus, as long as the deposition of the over-spray particles on theregeneratable separation element takes place in a dry manner, that is.

A “dry” separation device can also be provided with a “wet” cleaningdevice, as long as the deposition of the over-spray particles on theregeneratable separation element takes place in a dry manner, that is,without washing using a washing fluid.

Preferably the entire separation of wet paint over-spray from theexhaust air flow containing the over-spray particles takes placecompletely dry, that is, without use of a fluid for washing theover-spray particles out of the exhaust air flow.

Use of a regeneratable surface filter in the separation devicecircumvents the necessity of providing a washing station and theassociated water treatment. Thereby, the energy-consumption of theseparation device and (owing to the omission of the water treatment)also the space-requirements of the device are significantly reduced.

The capacity to be cleaned of the surface filter also further ensures along service life of the filter with large quantities of resulting wetpaint over-spray.

In view of the provision of a narrowed range in the exhaust air flowpath from the application area to the separation device, it isfurthermore achieved that the regeneratable surface filter is protectedagainst direct effects from the application area.

Thereby, that the central flow direction of the exhaust air flow inpassing the narrowed area remains essentially preserved, it is achievedthat a premature deposition of wet paint over-spray on the boundarywalls of the narrowed area is avoided.

In a preferred arrangement of the device according to the invention, thenarrowed area is located beneath the application area.

If the application area is arranged in a painting booth, then thenarrowed area is preferably disposed within a vertical projection of thebasal area of the painting booth.

To prevent the wet paint over-spray from the exhaust air flow fromalready settling on the boundary walls of the narrowed area, it is anadvantage if the elongation of the narrowed area in the flow directionof the exhaust air flow is shorter than approx. 6 m, preferably shorterthan approx. 1 m, in particular shorter than approx. 0.5 m.

If the application area is arranged in a painting booth with alongitudinal direction, then the narrowed area preferably extends in thelongitudinal direction of the painting booth over essentially the entirelength of the painting booth.

Thereby the narrowed area in the longitudinal direction of the paintingbooth can be divided into several narrowed sub-areas.

Alternatively, it can also be provided that the narrowed area in thelongitudinal direction of the painting booth is not divided.

If the application area is disposed in a painting booth with atransverse direction, it can be provided that the narrowed area in thetransverse direction of the painting booth is divided into severalnarrowed sub-areas.

Alternatively, it can also be provided that the narrowed area in thetransverse direction of the painting booth is not divided.

The entrance of the exhaust air flow into the narrowed area ispreferably arranged above the at least one regeneratable surface filter.

If the application area is disposed in a painting booth with atransverse direction, then the smallest cross-section of the narrowedarea flowed through by the exhaust air stream preferably has anextension in the transverse direction of the painting booth, whichamounts to at most approx. 20% of the extension of the painting booth inthe transverse direction of the painting booth.

In order for the at least one regeneratable surface filter to beprotected against damages, it is advantageous if at least one shieldingelement is arranged vertically over the at least one regeneratablesurface filter, which will prevent a vertical falling down of articles,dirt and/or paint particles from the application area upon theregeneratable surface filter.

Thereby it may be provided that the at least one shielding element formsthe boundary of the narrowed area.

In order for favorable flow conditions in the exhaust air flow path tobe obtained, it is desirable if the device contain at least oneflow-guidance element, which directs at least one portion of the exhauststream to the narrowed area.

Thereby the flow guidance element can feature an at least in sections,essentially horizontally aligned flow guidance surface.

Alternatively, it may also be provided that the flow guidance elementfeatures a flow guidance element inclined at least in sections againstthe horizontal, preferably towards the narrowed area.

If the device has a bottom, which limits the exhaust air flow pathdownward, it can be provided that at least one part of the bottom iscovered by an area separated from the area of the device flowed throughby the exhaust air. In this way the bottom surface area is reduced,which is contaminated by wet paint over-spray separating out of theexhaust air flow before reaching the at least one surface filter.Thereby, it can be provided that an upper boundary wall of the areaseparated from the area of the device flowed through by the exhaust airflow forms at least one part of a flow guidance element, which directsat least one portion of the exhaust air flow to the narrowed area.

If the application area is arranged in a painting booth and the devicecomprises at least one exhaust air duct, into which at least one portionof the exhaust air flow enters after passing the separation device, thena special space-saving structure of the device is achieved, if theexhaust air channel is disposed within a vertical projection of thebasal surface of the painting booth.

In order to facilitate the cleaning of the regeneratable surface filter,it is advantageous, if the at least one exhaust air channel exhibits abarrier layer comprising a pre-coat material which preventsagglutination of the filter surface.

For the barrier layer made of precoat-material to fabricate on thesurface filter, it can be provided that the device comprises at leastone pre-coat feeding apparatus, which delivers a pre-coat material inthe exhaust air flow.

Thereby, the supply of pre-coat material in the exhaust air flow cantake place continuously or in intervals.

As pre-coat materials, lime, aluminum silicates, aluminas, siliconoxides, powder coatings or the like are taken into consideration.

In principle, any medium is suitable as a pre-coat material which hasthe capacity to absorb the liquid portion of the wet paint over-spray.

Moreover it is possible, to arrange the at least one pre-coat feedingapparatus in direct connection to the application area, for example onthe bottom area of the painting booth.

But it is particularly advantageous if the at least one pre-coat feedingapparatus is disposed at the narrowed area of the exhaust air flow path.In the narrowed area of the exhaust air flow path high flow velocitiescontrol, so that by the feeding of the pre-coat material to thislocation a particularly good pre-coat distribution is obtained by meansof venturi turbulence.

With pre-coating there is the possibility of interim pre-coating,whereby a new pre-coating material is applied without prior cleaning ofthe surface filter, so that the later cleaning characteristics of thesurface filter are improved.

The at least one regeneratable surface filter of the separation deviceis preferably capable of being cleaned in intervals.

Alternatively or additionally it can thereby be provided that the atleast one regeneratable surface filter exhibits a moist surface in theoperation of the device.

The surface filter can be kept damp, for example, by use of rinsing- orhumidification media such as demineralized water, butylglycol or othersolvents, in order to facilitate the cleaning of the surface filter.

These humidification media can be introduced at the same locations inthe exhaust air stream as the previously described pre-coat materials.

For a basic cleaning of the filter surface of the surface filter it isadvantageous, if the surface of the at least one regeneratable surfacefilter is capable of being rinsed off continuously or in intervals.

Alternatively or additionally it can thereby be provided that the atleast one regeneratable surface filter is capable of being cleaned bycompressed air impulses.

A particularly energy-saving operation of the painting installation ispossible, if the device has an air circulation cycle, in which theexhaust air flow, from which the wet paint over-spray has beenseparated, is at least partially re-delivered to the application area.

Claim 30 directed to an installation for the painting of objects,particularly of vehicle bodies, which comprises at least one paintingbooth and at least one device according to the invention for separatingwet paint over-spray from an over-spray particle-containing exhaust airstream.

Further characteristics and advantages are the subject of the followingdescription and graphic illustration of exemplary embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages of the present invention will be readily appreciated asthe same becomes better understood by reference to the followingdetailed description when considered in connection with the accompanyingdrawings wherein:

FIG. 1 a schematic vertical cross-section through a first embodiment ofa painting booth with a device arranged under it for separating wetpaint over-spray from an over-spray particle-containing exhaust airstream, which includes two separation devices for separating theover-spray from the exhaust air stream and also two exhaust ducts, whichrun laterally to the left and/or right alongside the floor plan of thepainting booth, whereby a narrowed area of the flow path of the exhaustair stream is provided between an application area of the painting boothand the separation devices, which is bounded by horizontally alignedflow guidance elements;

FIG. 2 a schematic side view of the installation of FIG. 1;

FIG. 3 a schematic top view from above of the installation of FIGS. 1and 2;

FIG. 4 a schematic representation in perspective of the installation ofFIG. 1 to FIG. 3;

FIG. 5 a schematic representation of an air circulation cycle of theinstallation of FIGS. 1 to 4;

FIG. 6 a schematic representation in perspective of a regeneratablesurface filter of the installation of FIG. 1-FIG. 5;

FIG. 7 a schematic longitudinal section through the surface filter ofFIG. 6, which illustrates a cleaning process of the surface filter;

FIG. 8 a schematic representation in perspective of an alternativeembodiment of a regeneratable surface filter;

FIG. 9 a schematic cross-section through the surface filter of FIG. 8,which illustrates a cleaning process of the surface filter;

FIG. 10 a schematic top view from above the surface filter of FIGS. 8and 9;

FIG. 11 a schematic cross-section through a second embodiment of apainting booth with a device arranged under it for separating wet paintover-spray from an exhaust air stream containing over-spray particles,which includes two separation devices for separating the over-spray fromthe exhaust air stream and also two exhaust ducts, which run laterallyto the left and/or right alongside the floor plan of the painting booth,whereby a narrowed area of the flow path of the exhaust air stream isprovided between an application area of the painting booth and theseparation devices, which is bounded by flow guidance elements which areinclined against the horizontal;

FIG. 12 a schematic side view of the installation of FIG. 11;

FIG. 13 a schematic top view from above of the installation of FIGS. 11and 12;

FIG. 14 a schematic representation in perspective of the installation ofFIG. 11 to FIG. 13;

FIG. 15 a schematic cross-section through a third embodiment of apainting booth with a device arranged under it for separating wet paintover-spray from an exhaust air stream containing over-spray particles,which includes two separation devices for separating the over-spray fromthe exhaust air stream and also two exhaust ducts, which run laterallyto the left and/or right alongside the floor plan of the painting booth,whereby between an application area of the painting booth and theseparation devices a narrowed area of the flow path of the exhaust airstream is provided in the form of a shaft extending in a verticaldirection;

FIG. 16 a schematic side view of the installation of FIG. 15;

FIG. 17 a schematic top view from above of the installation of FIGS. 15and 16;

FIG. 18 a schematic representation in perspective of the installation ofFIG. 15 to FIG. 17;

FIG. 19 a schematic cross-section through a fourth embodiment of apainting booth with a device arranged under it for separating wet paintover-spray from an exhaust air stream containing over-spray particles,which includes a separation device for separating the over-spray fromthe exhaust air stream and an exhaust duct arranged within a verticalprojection of the basal surface of the painting booth;

FIG. 20 a schematic side view of the installation of FIG. 19;

FIG. 21 a schematic top view from above of the installation of FIG. 19and FIG. 20; and

FIG. 22 a schematic representation in perspective of the installation ofFIGS. 19 to 21.

Equal or functionally equivalent elements are designated in the figureswith the same reference symbols.

DETAILED DESCRIPTION

An installation shown in FIGS. 1 to 7, marked 100 as a whole for thespray-coating of vehicle bodies 102 which includes a clearlyschematically represented conveyer device 104, by means of which thevehicle bodies 102 can be moved along in a conveying direction 106through an application area 108 of a painting booth marked 110 as awhole.

The conveying device 104 can, by way of example, be constructed as aninverted circular conveyer or as an inverted monorail conveyer.

In particular the conveyer device 104 can be formed in two parts and—asbest understood from FIGS. 1, 3 and 4—includes two conveyer belts 104 aand 104 b extending parallel to the conveyer 106, which are spaced apartfrom one another in a horizontal direction perpendicular to the conveyer106.

The application area 108 is the interior chamber of painting booth 110,which perpendicular of it to the conveyer 106, which corresponds to thelongitudinal direction of the painting booth 110, it is limited,respectively, by a booth wall 114 running in horizontal transversedirection 112 on both sides of the conveyer device 104.

On both sides of the conveyer device 104 spray-painting devices 116 (seeFIGS. 1-4) are arranged in the painting booth 110, for example, in theform of paint application robots.

By means of a compressed air production device 118 schematicallyrepresented in FIG. 5 an air stream is produced which essentiallypervades the application area vertically from top to bottom, asindicated by the arrow 119 in FIG. 1.

This air stream takes up paint over-spray in the form of over-sprayparticles in the application area 108.

The term “particle” includes solid as well as liquid components,particularly drops.

A wet paint is used for coating in the installation 100, thus the wetpaint over-spray consists of paint drops.

Most of the over-spray particles have a largest size of in a range fromapprox. 1 gm to approx. 100 pm.

The exhaust air flow designated by the arrow 120 leaves the paintingbooth 110 through a booth bottom 122, which contains an air-permeablelattice grate 124.

The installation 100 also includes a device marked 126 as a whole, forseparating wet paint over-spray from the air flow 120, which is arrangedbeneath the application area 108.

The device 126 includes an essentially quadrangular-shaped flow chamber128, which reaches over into the conveyer 106 over the whole length ofthe painting booth 110 and is bounded in the transverse direction 112 ofthe painting booth 110 by vertical side-walls 130, which alignessentially with the lateral booth-walls 114 of the painting booth 110,so that the flow chamber 128 has essentially the same horizontalcross-sectional area as the painting booth 110 and is arrangedessentially completely within the vertical projection of the basalsurface of the painting booth 110.

The flow chamber 128 is subdivided by flow guidance elements 132, whichin this exemplary embodiment are formed as essentially horizontal flowguidance plates 134, into an upper section 136 and a lower section 138.

The upper section 136 and lower section 138 of the flow chamber 128 areconnected to each other by a narrowed area 140, which is in the form ofa space 142 between the free borders opposite to each other of the flowguidance elements 132 and which forms a narrowing in the flow path ofthe exhaust air stream 120 through the flow chamber 128.

The upper sides of the flow guidance elements 132 form in each case aflow guidance surface 135, which directs the exhaust air stream to thenarrowed area 140.

A pre-coat feed device 144 is arranged at the narrowed area 140 of theflow path, which continuously or interval-wise supplies a pre-coatmaterial into the exhaust air stream 120.

The pre-coat feed device 144 can, for example, be designed as a pre-coatspray nozzle, which supplies the pre-coat material in the form of aspray mist into the exhaust air stream 120.

The arrangement of the pre-coat feed device 144 at the narrowed area 140of the exhaust air stream 120 offers the advantage, that there due tothe elevated flow velocity of the exhaust air stream 120 and because ofthe small passage cross-section, turbulences appear in the exhaust airstream, which make possible a swirling of the pre-coat material in theexhaust air stream 120 and consequent particularly good distribution ofthe pre-coat material in the exhaust air stream 120.

The pre-coat supply device 144 is attached to a (not shown) pre-coatfeed pipe which feeds the pre-coat material in flowable condition via a(not shown) pre-coat feed pump from a (not shown) pre-coat storagecontainer.

In principle, any medium is suitable as a pre-coat material which hasthe capacity to absorb the liquid portion of the wet paint over-spray.

For example, as pre-coat materials, lime, aluminum silicates, aluminas,silicon oxides, powder coatings or the like are taken intoconsideration.

In order to make the pre-coat material flowable and sprayable, i.e.aqueous dispersions of the aforementioned materials are used.

If the filter sequential to the pre-coat feed device 144 is not to bepre-coated, but should only be moisturized, then also only amoisturizing medium can be introduced into the exhaust air stream 120 bymeans of the pre-coat feed device 144.

As such, moisturizing media in particular i.e., demineralized water,butylglycol or other solvents are taken into consideration.

A separation device 145 for separating wet paint over-spray from theexhaust air stream 120 is provided in the lower section 138 of the flowchamber 128 on both sides, respectively, of the narrowed area 140. Theseparation devices 145 include several regeneratable surface filters146, spaced apart from each other on the conveyer 106, arranged,respectively, opposite to one another on both sides of the verticalside-walls 130 of the flow chamber 128, which with their filter elements148 extend into the lower section 138 of the flow chamber 128 (see inparticular FIGS. 1, 2 and 4).

This regeneratable surface filter 146 is shown in detail in FIGS. 6 and7.

Each of the regeneratable surface filters 146 contains a hollowfundamental body 150, to which several, for example, four filterelements 154 are attached.

Filter elements 154 are, for example, are formed essentially in a plateshape and preferably feature, as is seen from FIG. 6, a serratedcross-section, in order for the available filter surface 156 to beenlarged.

The filter elements 154 can be formed, for example, as plates made fromsintered polyethylene, which are provided with a polytetrafluoroethylene(PTFE) membrane on their outer surface.

Alternatively or additionally, it can also be provided that the filterelements 154 are made of a non-woven fabric with a PTFE coating.

For this reason, the PTFE coating serves, as the case may be, to raisethe filter quality of the surface filter 146 (that is, to diminish its'permeability) and also to prevent the permanent adhesion of the wetpaint over-spray deposited from the exhaust air stream 120.

Both the base material of the filter element 154 and its' PTFE-coatingexhibit a porosity, so that the exhaust air can pass through the poresinto the interior space 176 of the respective filter element 154.

To prevent the agglutination of the filter surface 156, it is furtherprovided with a barrier layer formed from the pre-coat material suppliedin the exhaust air stream 120.

This barrier layer easily forms itself in the operation of device 126 bydeposition on the filter surface 156 of the pre-coat material releasedin the exhaust air stream 120.

Preferably, the amount of pre-coat material released into the exhaustair stream 120 is regulated, so that the thickness of the barrier layermade from the pre-coat material on the filter element 154 of theregeneratable surface filter 146 is in the range of i.e. approx. 150 pmto 20011 m.

The exhaust air stream 120 overcoats the filter surfaces 156 of thefilter element 154 of the regeneratable surface filter 146, whereby boththe carried pre-coat material and also the carried wet paint over-sprayis deposited upon the filter surfaces 156, and passes through the porousfilter surfaces 156 into the interior space 176 of the filter element154, which are connected with the hollow space within the fundamentalbody 150.

The purified exhaust air stream 120 thus by going through thefundamental body 150 passes, respectively, into an exhaust air pipet158, which leads from the respective regeneratable surface filter 146 toan exhaust air duct 160 on the side next to a vertical side-wall 130 ofthe flow chamber 128, which duct runs parallel to conveyer 106.

As is clear from the schematic representation of FIG. 5, the purifiedexhaust air from the wet paint over-spray passes out of the two exhaustair ducts 160 at least partially back to the air flow production device118, which conducts the purified exhaust air via a supply line 162 onceagain to the application area 108 in the painting booth 110.

Another part of the purified exhaust air stream is delivered via anexhaust air blower 164 in an exhaust air supply line 166 to thesurrounding area.

This part of the exhaust air stream delivered to the surrounding area isreplaced by fresh air, which is fed to the air flow production device118 via a fresh air supply line 168.

The main part of the air led through the application area 108 is thusguided in an air circulation cycle 170, which includes the airproduction device 118, the supply line 162, the application area 108,the flow chamber 128 and the exhaust air duct 160, whereby a constantheating of the fresh delivered supply air is avoided and thereby theenergy costs are significantly lowered.

Since the separation of the wet paint over-spray from the exhaust airstream 120 by means of the regeneratable surface filter 146 takes placedry, that is, without washing with a cleaning fluid, the air guided inthe air circulation cycle 170 is not humidified in the separation of thewet paint over-spray, so that no devices for humidification of the airguided in the air circulation cycle 170 are necessary at all.

Furthermore, no devices are necessary for separating the wet paintover-spray from a washout-cleaning fluid.

The regeneratable surface filter 146 is cleaned by compressed airimpulses in determined time intervals, when its' coating by wet paintover-spray reaches a preset amount.

This cleaning can take place, i.e. one time per work shift, that is, twoor three times per work day.

The required compressed air impulse is produced by a compressed airreservoir 172, which is arranged at the fundamental body 150 of therespective regeneratable surface filter 146 and thereby is in theposition, to deliver compressed air impulses to a compressed air pipe174, which runs within the respective fundamental body 150 and leadsfrom the compressed air reservoir into the interior space 176 of thefilter element 154.

From the interior spaces 176 of the filter element 154 the compressedair impulse passes through the porous filter surfaces 156 into the outerspace of the filter element 154, whereby the barrier layer formed frompre-coat material on the filter surfaces 156 and the wet paintover-spray deposited on the filter surfaces 156 are dissolved, so thatthe filter surfaces 156 are converted back into their cleansed originalcondition.

The flow direction of the compressed air through a regeneratable surfacefilter 146 during the cleaning is designated in FIG. 7 by the arrow 177.

The compressed air reserve in the compressed air reservoir 172 isreplenished by (not shown) compressed air supply lines from an on-sitecompressed air network.

A cleaning by compressed air impulses can alternatively or additionallybe modified such that the regeneratable surface filter 146 is washed outby means of suitable spray device in specified intervals, in order toremove the wet paint over-spray deposited on the filter surfaces 156.

As is best seen from FIGS. 1 and 2, the material cleaned off from thefilter surfaces 156 of the regeneratable filter 146 arrives at acollecting belt 178 at the bottom of the flow chamber 128, which isdesigned, i.e. as a endless belt circulating via a driven roller 180 anda non-driven guide roller 182.

The driven roller 180 is made to rotate by means of a drive motor 184,in order to shift the collection belt 178 in motion lengthwise of theconveyer 106.

In this way, via the collection belt 178 the material deposited on thesurface of the collection belt 178 from the regeneratable surface filter146, which includes pre-coat material and deposited wet paintover-spray, is transported to a (not shown) separating device, fromwhich this material (i.e. by means of a stripping device) is dissolved,collected and if necessary, recycled.

The collection belt 178 also takes up a part of the wet paint over-spraywhich deposits directly from the exhaust air stream 120 onto thecollection belt 178, before the exhaust air stream 120 reaches theregeneratable surface filter 146.

An alternative development of the regeneratable surface filter 146,which is usable in the device 126, is shown in FIGS. 8 to 10.

The regeneratable surface filter 146 includes instead of multiple,vertically oriented plate-shaped filter elements arranged next to oneanother, an essentially cylindrical filter element 154′, which alsocontains, viewable in the cross-section, a serrated filter surface 156for enlargement of the available filter surface 156.

In addition, in this embodiment for production of the compressed airimpulse, a rinsing liquid loop 186 is provided for cleaning of theregeneratable surface filter 146, which sprays a rinsing liquid throughto the radial inner surface of the rinsing liquid delivery port of therinsing liquid loop 186 against the filter surface 156 of the filterelement 154′, so that the rinsing liquid dissolves the barrier layer andthe wet paint over-spray deposited on the filter surface 156 and carriedon the collection belt 178.

The second embodiment shown in FIGS. 11-14 of an installation 100 forpainting of vehicle bodies 102 is thereby distinguished from theabove-mentioned first embodiment, in that the flow guidance elements132, which divide the lower section 138 from the upper section 136 ofthe flow chamber 128 of the device 126 for separation of the wet paintover-spray, are not in this second embodiment, in contrast to the firstembodiment, aligned essentially horizontally, but rather, as is bestseen from FIG. 11, but are inclined against the horizontal, so that theyslope towards the narrowed area 140.

The angle of inclination against the horizontal is preferably approx. 5°to approx. 30°.

Via this inclination of the flow guidance elements 132 and therewith theflow line surfaces 135 at their top side, a funnel-shaped form of thelower area of the upper section 136 of the flow chamber 128 is obtained,through which the air stream is comparatively measured out to thenarrowed area 140 and the extent of turbulences at the top side of theflow guidance elements is reduced. In this way, a lesser portion of thewet paint over-spray is already deposited on the flow line surfaces 135,before the air stream 120 reaches the lower section 138 of the flowchamber 128.

Furthermore, the flow guidance elements 132 in the second embodiment areset somewhat higher within the flow chamber 128 than in the firstembodiment.

Apart from that, the second embodiment shown in FIGS. 11 to 14, of aninstallation 100 for painting vehicle bodies 102 agrees with respect tostructure and function with the first embodiment shown in FIGS. 1-10,insofar as its' aforementioned description is concerned.

A third embodiment shown in FIGS. 15-18 of an installation 100 forpainting vehicle bodies 102 is thereby distinguished from the previouslydescribed second embodiment, in that the narrowed area 140 is formed notonly by a space 142 between the borders arranged opposite to each otherof the flow guidance elements 132, but rather includes an exhaust airshaft 188 extending vertically downwards from borders arranged oppositeto each other of the flow guidance elements 132, which is bounded onboth its' side-walls by vertical side-wall ducts 190 extending in theconveyer 106.

Between the lower border of each side-wall duct 190 and the top side ofthe collection belt 178 a vertical space 192 is respectively formed,through which the exhaust air stream exits from the narrowed area 140into the lower section 138 of the flow chamber 128, whereby the lowersection 138 of the flow chamber 128 in this embodiment is divided intotwo sub-areas 138 a, 138 b arranged on the side of the exhaust air shaft188.

Furthermore, in this embodiment the filter elements 154 of theregeneratable surface filter 146 do not extend in essentially horizontaldirection into the lower section 138 of the flow chamber 138, but ratherare inclined to a greater degree against the horizontal, and in fact areinclined preferably at about the same angle as the flow guidancesurfaces 135 of the flow guidance elements 132.

This angle of inclination against the horizontal is preferably in therange from approx. 5° to approx. 30°.

On the basis of this inclination of the filter elements 154 of theregeneratable surface filter 146 opposite to the horizontal, thefundamental body 150 of the regeneratable surface filter 146 and the toparea of the side-walls 130 of the lower section 138 of the flow chamber128 are also not vertically aligned, but rather are inclined against thevertical around a sharp corner, which corresponds to the angle ofinclination of the filter elements 154 and the flow guidance surfaces135 towards the horizontal.

In this embodiment the regeneratable surface filters 146 are especiallywell protected against objects falling from the application area 108.

Moreover, the top section 136 and the lower section 138 of the flowchamber 128 are fluidic decoupled from each other by the air exhaustshaft 188, so that the exhaust air stream in the lower section 138 ofthe flow chamber 128 is independent to a large extent from the flowconditions in the top section 136 of the flow chamber 128.

Since in this embodiment two spaces 192 are present, through which theexhaust air stream 120 enters into the lower section 138 of the flowchamber 128, two pre-coat feeding devices 144 are also provided, whichrespectively are arranged adjacent to one of the vertical spaces 192 atthe lower end of one of the shaft side-walls 190.

In addition, the third embodiment shown in FIGS. 15-18 of aninstallation 100 for painting of vehicle bodies 102 agrees with respectto structure and function with the first embodiment shown in FIGS.11-14, insofar as its' aforementioned description is concerned.

A fourth embodiment shown in FIGS. 19-22 of an installation 100 forpainting of vehicle bodies 102 is thereby distinguished from thepreviously described first embodiment, in that the device 126 forseparating wet paint over-spray from the exhaust air stream 120 is notsymmetrical to the longitudinal central plane 194 of the painting booth110, but rather is asymmetrical to this longitudinal central plane 194.

In particular, the regeneratable filter surfaces 146 in this embodimentare arranged only on one side of the longitudinal central plane 194(namely, see the side depicted on the left in FIG. 19).

In this embodiment only a single exhaust air duct 160 is provided, whichhowever is not arranged on the side outside of the side-wall 130 of theflow chamber 128, but instead is integrated into the flow chamber 128,and is arranged directly under one of the flow guidance elements 132, sothat the affected flow guidance element 132 forms an upper boundary ofthe exhaust air chamber 160.

In this embodiment, the regeneratable surface filters 146 are notconnected via exhaust air pipe 158 with the exhaust air chamber 160, butrather are arranged directly at a lower boundary wall 196 of the exhaustair chamber 160, whereby the filter elements 154 of the regeneratablesurface filter 146 hang down in essentially vertical direction from thelower boundary wall 196 of the exhaust air duct 160 into the lowersection 138 of the flow chamber 128.

By this pendent arrangement, a particularly efficient cleaning of theregeneratable surface filter 146 is obtained.

The side of the flow guidance chamber 128 lying opposite to the side ofthe lower section 138 of the flow chamber 128 which is provided with theregeneratable surface filter 146 is separated by a vertical dividingwall 198 from the region of the lower section 138 of the flow chamber128 which is flowed-through by the exhaust air flow stream 120.

This separated area 200 is upwardly bordered by one of the flow guidanceelements 132 and extends downwards up to the base 202 of the flowchamber 128.

This area 200 which is separated from the flowed-through chamber 128can, for example, be used for the uptake of auxiliary attachments, suchas blowers, storage containers, pumps or the like.

Alternatively or additionally, it is possible to use the separated area200 as an air duct, i.e. as an additional exhaust air duct, fresh airsupply duct or exhaust air discharge duct.

The flowed-through area of the lower section 138 of flow chamber 128 isbordered downwards by the collection belt 178.

In particular it is clear from FIG. 20 that the collection band 178 isnot cleaned in the area of its' non-driven guide roller 182 via astripping device 204 of the material collected from the surface of thecollection belt 178, which contains pre-coat material and deposited wetpain over-spray, whereby the material stripped-off by the collectionbelt 178 is deposited into a mobile storage container 206.

If in the mobile storage container 206 a specified highest fill level isreached, the mobile storage container 206 is exchanged for an emptymobile storage container and the filled mobile storage container 206 isconveyed to a (not shown) collection and recycling station.

Since in the fourth embodiment shown in FIGS. 19-22 all components ofthe device 126 for separating wet paint over-spray are arranged withinthe vertical projection of the basal surface of the painting booth 110,this embodiment is particularly compact in construction and is speciallysuited for crowded space conditions.

Moreover, the fourth embodiment shown in FIGS. 19-22 agrees in respectto structure and function with the first embodiment shown in FIGS. 1-10,insofar as its previous description is concerned.

Obviously, many modifications and variations of the present inventionare possible in light of the above teachings and the foregoing inventionhas been described in accordance with the relevant legal standards;thus, the description is merely exemplary rather than limiting innature. Variations and modifications to the disclosed embodiment maybecome apparent to those skilled in the art and do come within the scopeof the invention. Accordingly, the scope of the legal protectionafforded this invention can only be determined by studying the followingclaims.

1-30. (canceled)
 31. Installation for painting objects, in particularvehicle bodies, comprising at least one painting booth and at least onedevice for separating wet paint over-spray from an over-sprayparticle-containing exhaust air stream, wherein the overspray particlespass into the exhaust air stream in an application area of the paintinginstallation; wherein the device for separating wet paint over-sprayfrom the exhaust air stream comprises at least one separation device forseparating the over-spray from at least a part of the exhaust airstream, which has at least one filter element, wherein the flow path ofthe exhaust air stream from the application area to the separationdevice has at least one narrowed area, wherein the device for separatingwet paint over-spray from the exhaust air stream includes at least onepre-coat supply device which is disposed at the narrowed area of theflow path of the exhaust air stream and delivers a pre-coat materialinto the exhaust air stream, and wherein at least one filter element hasa barrier layer including the pre coat material, which preventsagglutination of a filter surface.
 32. Installation according to claim31, wherein the narrowed area is disposed beneath the application area.33. Installation according to claim 31, wherein the painting booth has alongitudinal direction, and wherein the narrowed area extends in thelongitudinal direction of the painting booth over substantially theentire length of the painting booth.
 34. Installation according to claim31, wherein the painting booth has a longitudinal direction, and whereinthe narrowed area is divided in the longitudinal direction of thepainting booth into a plurality of narrowed sub-areas.
 35. Installationaccording to claim 31, wherein the painting booth has a longitudinaldirection, and wherein the narrowed area is not sub-divided in thelongitudinal direction of the painting booth.
 36. Installation accordingto claim 31, wherein the painting booth has a transverse direction, andwherein the narrowed area is divided into a plurality of narrowedsub-areas in the transverse direction of the painting booth. 37.Installation according to claim 31, wherein the painting booth has atransverse direction, and wherein the narrowed area is not sub-dividedin the transverse direction of the painting booth.
 38. Installationaccording to claim 31, wherein the entrance of the exhaust air streaminto the narrowed area is disposed above the at least one filterelement.
 39. Installation according to claim 31, wherein the device forseparating wet paint over-spray from the exhaust air stream includes atleast one flow guidance element, which directs at least a portion of theexhaust air stream to the narrowed area.
 40. Installation according toclaim 39, wherein the flow guidance element exhibits at least one flowguidance surface which is, at least in a section thereof, substantiallyhorizontally aligned.
 41. Installation according to claim 39, whereinthe flow guidance element exhibits at least one flow guidance surfacewhich is, at least in a section thereof, inclined against thehorizontal.
 42. Installation according to claim 31, wherein the devicefor separating wet paint over-spray from the exhaust air stream has abase, which limits the flow path of the exhaust air stream downwards,and wherein at least a part of the base is covered by an area separatedfrom an area of the device for separating wet paint over-spray from theexhaust air stream flowed-through by the exhaust air stream. 43.Installation according to claim 42, wherein the device for separatingwet paint over-spray from the exhaust air stream includes a top boundarywall of the area separated from the area of the device for separatingwet paint over-spray from the exhaust air stream flowed-through by theexhaust air stream, which top boundary wall forms at least a part of aflow guidance element, which directs at least a part of the exhaust airstream to the narrowed area.
 44. Installation according to claim 31,wherein the supply of the pre-coat material into the exhaust air streamtakes place continuously.
 45. Installation according to claim 31,wherein the supply of the pre-coat material into the exhaust air streamtakes place in intervals.
 46. Installation according to claim 31,wherein the at least one filter element is capable of being cleaned inintervals.
 47. Installation according to claim 31, wherein the at leastone filter element exhibits a moist surface in the operation of thedevice for separating wet paint over-spray from the exhaust air stream.48. Installation according to claim 47, wherein a surface of the atleast one filter element is capable of being rinsed-off continuously orin intervals.
 49. Installation according to claim 31, wherein the atleast one filter element is capable of being cleaned by compressed airpulses.
 50. Installation according to claim 31, wherein the device forseparating wet paint over-spray from the exhaust air stream contains anair circulation circuit, in which the exhaust air stream, from which thewet paint over-spray has been separated, is at least partially suppliedto the application area again.
 51. Installation according to claim 31,wherein the installation comprises a collection belt for receivingpre-coat material and wet paint over-spray from a plurality of filterelements and for transporting the pre-coat material and the wet paintover-spray along a conveying direction of the objects to be painted. 52.Installation according to claim 31, wherein the passage cross-section atthe narrowed area is so small that turbulences appear in the exhaust airstream, which distribute the pre-coat material in the exhaust airstream.
 53. Installation according to claim 31, wherein the pre-coatmaterial comprises lime, an aluminum silicate, an aluminum oxide, asilicon oxide or coating powder.